ES2272489T3 - INSULATION PRODUCT IN THERMAL PARTICULAR THAT CONTAINS A BINDER BASED ON FORMO-PHENOLIC RESIN AND ITS MANUFACTURING. - Google Patents

Abstract

Insulating product based on mineral wool glued with a binder based on a form-phenolic resin, characterized in that the binder comprises in mixture: - 60 to 90 parts by weight of a phenol-formaldehyde resol having a free formaldehyde rate less than or equal to 25% by weight with respect to the dry weight of resin and a free phenol rate less than or equal to 2.5% by weight with respect to the dry weight of resin obtained by condensation in basic phenol medium (P) and formaldehyde (F) in a molar ratio F / P of the order of 2.5 to 4 until the condensation product neutralized by sulfuric acid has a dilution with water greater than 500% and less than or equal to 1500 %; - - 10 to 40 parts by weight of urea.

Description

Particular thermal insulation product containing a resin based binder Formo-phenolic and its manufacture.

The present invention relates to the scope of insulation products, in particular thermal or phonic, to mineral wool base and an organic binding agent based on a phenol-formaldehyde resin. Refers more specifically to reduce pollution emissions various during the manufacture of such wool-based products Mineral comprises a first stage of manufacturing the same wool by drawing and stretching, and a stage of putting in form in which mineral wool is collected on a receiving organ in the form of a reinforcing layer To ensure the cohesion of the reinforcement layer, it is projected on the wool during its journey to the organ receiver a sizing composition, which contains a resin hardenable The reinforcing layer thus treated is subjected to then a heat treatment in an oven to crosslink the resin and obtain a product that has desired properties, such as dimensional stability, mechanical strength, thickness recovery after compression, homogeneous color.

The sizing compositions are presented generally in the form of an aqueous composition containing a Formo-phenolic resin and additives such as resin hardening catalyst, silane promoter adhesion, mineral dust oils ...

So that the composition is apt to be distributed as generally as possible by spraying, it is convenient that the resin is sufficiently dilutable with water. To that end, it is customary to conduct the condensation reaction between formaldehyde and phenol limiting the degree of condensation of monomers, to prevent the formation of long chains, little hydrophilic that reduce the dilution. Consequently, the resin it contains a certain proportion of monomers that have not reacted, in particular formaldehyde whose volatility can lead to undesirable emissions of organic compounds in the atmosphere of the factory.

This is the reason why, it is done generally react the condensation product form-phenolic with urea that traps the formaldehyde free forming nonvolatile condensation products. The presence urea in the resin also provides an economic advantage important linked to its low cost, since it can be entered in relatively large amount without significantly affecting the resin qualities versus properties in particular mechanics of the final product, significantly reducing the total cost of the resin.

However it was noted that this solution was not entirely satisfactory in terms of pollution atmospheric, as condensation products urea-formaldehyde revealed little stability at heat, so that during the use of the resin for the gluing of the mineral wool, during which the resin is subjected to temperatures above 100 ° C the condensation product urea-formaldehyde gives again, under the effect of heat, urea, formaldehyde and ammonia, which are released into the atmosphere of the fabric.

The present invention aims to make the manufacture of insulating products less polluting, more specifically as regards ammonia emissions in the manufacturing line, without penalizing the production cost of the insulating product

The invention is based on the finding that it is possible to significantly reduce emissions from ammonia in the manufacture of an insulating product using the at the same time a glue that retains a certain proportion of urea and which is, therefore, of a competitive cost.

In this regard the object of the invention is insulating product based on mineral wool glued with an agent binder based on a formho-phenolic resin, characterized in that the binder comprises in mixture:

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 60 to 90 parts by weight of a phenol-formaldehyde resol that has a free formaldehyde rate of 25% or less (in weight with respect to the dry weight of resin) and a free phenol rate less than or equal to 2.5% by weight with respect to the dry resin weight obtained by condensation in basic medium of phenol (P) and of formaldehyde (F) in a F / P molar ratio of the order of 2.5 to 4 until the acid neutralized condensation product sulfuric acid has a dilution with water greater than 500% and less or equal to 1500%; Y

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10 a 40 parts by weight of urea.

According to the invention, the free phenol rate by pushing the condensation reaction to a sufficient degree for an almost complete consumption of this raw material minority With an F / P ratio greater than 1, but not higher preferably less than or equal to 3.2, condensation is done forming species of moderately high molecular weight, with, by therefore, a consumption of formaldehyde higher than that would lead to very long chains of phenol-formalin condensates.

Then, once the reaction of condensation of the resol, the formaldehyde molecules are captured that they are still present in free form, by means of urea whose quantity it can be all the more reduced the lower the formalin rate free of resol.

It is thus possible to limit the proportion of urea in the binder agent mixture, while keeping low contents of free volatile organic compounds in the agent binder. It is therefore possible to limit emissions from volatile organic compounds such as phenol and formalin, reducing at the same time the amount of ammonia released in the line of manufacturing.

To control the development of the reaction of formation of the resol under the conditions required for the invention, three characteristic quantities are measured:

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 the free phenol and formalin rate that characterizes the development of the reaction,

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 the diluted neutralized resol that characterizes the length of the condensates formed.

According to the invention, the rate of free phenol in the resol before urea addition is less than or equal to 2.5% in phenol weight with respect to the dry resin weight, for a resol of dry extract of the order of 35 to 45%. Preferably the rate of Free phenol is less than or equal to 2% with respect to the dry weight of resin, advantageously less than or equal to 1.7% with respect to weight resin dry It may be, in particular, of the order of 0.5 to 1.7%, for example from 0.7 to 1.6% with respect to the dry weight of resin.

The rate of free formaldehyde in the resol is less than or equal to 25% dry weight of resin for a resol of dry extract between 35 and 45. preferably, the rate of Free formaldehyde is less than or equal to 20% with respect to weight resin dry, advantageously at 15.5%, in particular at 12%. It may be, in particular, of the order of 2 to 4%.

The resolvability of the resol corresponds to the factor of maximum dilution of the resol for which the formation of a permanent dilution disorder. The dilution by volume of water, as a percentage of volume of resol, which can be added to the resol before causing the formation of a permanent disorder. Thus, a dilution of 1500% means that 10 ml of resin can be diluted with 15x10 ml of water without the mixture becoming cloudy. In general and according to invention, this measurement is made using water dilution tempered deionized, that is, a water at room temperature, of the order of 15 to 25 ° C, generally about 20 ° C (in this temperature range, dilution does not vary so significant).

According to the invention, the development of condensation by measuring the solubility of the neutralized resol by sulfuric acid In fact, it is generally found that the resol synthesized in basic medium has a high dilution to pH basic (generally at pH 9) with a relatively low variation, even when it contains very high molecular weight species. To the On the contrary, when the resol is neutralized with sulfuric acid, the dilutability varies clearly decreasing when the weight Molecular concentration of phenol-formol condensates increases. It is thus possible to follow the appearance of compounds of molecular weight not wanted.

According to the invention, the resols used are characterized, therefore, by a dilution greater than 500 and less than or equal to 1500% in the acid neutralized state sulfuric; preferably, the dilution is more than 500 to 1000% in the neutralized state. By neutralization, the adding an amount of H 2 SO 4 sufficient to react with all OH - hydroxyl introduced by the basic catalyst

Such resoles can be advantageously synthesize by reacting phenol and formaldehyde, in presence of a basic catalyst such as soda, at a temperature of the order of 50 to 80 ° C, in particular 60 to 75 ° C, in particular approximately 70 ° C, for a duration of the order of 80 to 200 minutes, in particular, from 90 to 150 minutes, the duration being much shorter when the temperature is high and / or the F / P ratio  it is low. In this regard, an F / P ratio limited to 3.2 is preferably to avoid a reaction time that is too high.

The basic catalyst, known per se, in in particular, soda and also potash, lime or barite, generally used in quantity corresponding to 6 to 20 moles of hydroxyl OH equivalents for 100 moles of initial phenol. The phase hot condensation is usually followed by a progressive cooling to room temperature.

To prevent an unwanted continuation of the condensation reaction, it is desirable to disable catalysis basic neutralizing the resol. No neutralization is indicated by sulfuric acid because it reduces the dilution below 1500%, which is generally the maximum limit that guarantees a good ability to use spray online.

Thus, the resol used according to the invention is advantageously neutralizes by at least one acid chosen from the boric acid or an equivalent borate (in particular, borate ammonium, sodium metaborate, sodium tetraborate, polyborate amino alcohol), sulfamic acid or an equivalent sulfamate, a amino acid (in particular, aspartic acid, glutamic acid, aminoacetic ...). These acids have the property of modify the resol in such a way that its dilution is higher in the neutralized medium thus obtained than in the medium obtained with sulfuric acid. The neutralization is advantageously done until the obtaining a pH of the order of 7 to 9.

The neutralization product by one of the acids mentioned above of a resol presenting the characteristics of the invention generally have a dilution greater than 1000% and that reaches more than 2000% (you have the habit of saying that a dilution greater than 2000% is infinite) just after neutralization, and retains a dilution greater than or equal to 1000% after 3 weeks of storage at approximately 12 ° C under little agitation.

As a variant, the resol can be neutralized with any acid but in the presence of an emulsifier such as a gum and / or an anionic surfactant, in particular guar and ghatti gums, or possibly casein. The acid used can then be chosen from among all strong acids known per se, such as sulfuric acid, hydrochloric acid, and also boric acid, sulfamic acid (or equivalent salts) or a
amino acid

The preparation of a binding agent Usable according to the invention comprises the cold mixing of a resol as described above with urea in quantity limited According to the invention, the mixture comprises 60 to 90 parts in resol weight (counted by weight of resol matter dry matter) for 40 to 10 parts by weight of urea. Preferably, the mixture it comprises at least 65 parts, in particular 70 to 85 parts in dry weight of resol for at most 35 parts, in particular 15 to 30 parts by weight of urea.

The addition of urea can be done immediately after resol cooling, preferably after neutralization, so that it forms a stable premix to the storage, later usable for the formulation of glued, or it can be done at the same time of the gluing formulation before a manufacturing campaign. The utilization of urea in premix may however be preferred because it generates less emissions of pollutants, it includes Ammonia in the manufacturing line.

Urea is not the only compound usable as formaldehyde collector and can be added in particular by another Sulfite side of ammonium, at a rate of 1 to 20 parts by weight, in in particular, from 1 to 10 parts by weight for 100 parts by dry weight of resol + urea mixture. It was revealed that ammonium sulphite does not affect very noticeably to ammonia emissions, despite the contribution of ammonium ions that is constituted in the gluing. Do not However, it is preferable to limit the ammonium sulphite content to about 1 to 5 parts by weight, in particular, around 2 parts by weight for 100 parts by weight of dry resin and urea.

The sizing composition may on the other hand contain the other usual ingredients, such as:

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ammonium sulfate as a catalyst for hardening, preferably at the rate of 1 to 5 parts by weight to 100 parts by weight of dry matter resin and urea;

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one or more silicones;

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one or more mineral oils

Generally, a sizing composition can understand ammonia on the other hand. To minimize the gaseous ammonia emissions in the manufacturing line, is it is preferable that the glue be completely free of ammonia. Do not However, it turned out that an ammonia content less than or equal to 5 parts by weight of 20% solution for 100 parts by weight of matter dry resin + urea allows to remain below the maximum limit admissible for manufacturing in good condition.

The proportion of gluing in the product insulation is generally of the order of 1 to 12% by weight of matter dry with respect to the total weight of mineral wool.

The object of the invention is also a sizing composition as described above.

According to another aspect, the invention has for object of the use of a sizing composition as described above to reduce ammonia emissions in the manufacture of an insulating product.

According to the invention, the limits of Ammonia emissions up to less than 10 grams of ammonia per kilogram of mineral wool, in particular less than 8 g / kg, in particular, at most 5 g / kg.

The invention therefore also has object a manufacturing process of an insulating product to mineral wool base glued with a binding agent form-phenolic as described above, in which the accumulated ammonia emissions at all stages of manufacture are less than 10 grams of ammonia per kilogram of mineral wool.

The invention is illustrated by the examples. following.

Example 1

A resin is prepared form-phenolic introducing into a low reactor agitation that will be maintained throughout the manufacturing cycle, 100 kg of phenol and 241 kg of formaldehyde in 37% aqueous solution, and the temperature in the reactor is brought to 45 ° C. Molar relationship formaldehyde / phenol is 2.8.

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While maintaining the temperature at 45 ° C, are introduced regularly, in a time of 30 minutes, 12.7 kg of sodium hydroxide in 47% aqueous solution, either with a 6% soda / phenol weight ratio, or a ratio 14.1% molar.

Immediately after the end of this addition, the temperature is increased to 70 ° C in 30 minutes, and Maintains this temperature for a time of about 120 minutes. At the end of this time, the solubility of the neutralized resol Sulfuric acid is 1200%.

The reactor and the mixture are then cooled of the reaction from 70 ° C to 35 ° C in 35 minutes.

The pH of the medium of the reaction at 7.2 with sulfamic acid in 15% aqueous solution (approximately 88 kg). The operation takes 90 minutes approximately, while cooling the reaction mixture at 20 ° C.

The neutralized resol has a rate of free formalin of 2.5% by weight of the resol, either 6.8% with regarding the dry matter weight of the resin, and a phenol rate free of 0.5% by weight of the resol, for a dry extract of 37%, or Good 1.4% compared to dry.

The solubility of the resol neutralized by the sulfamic acid is infinite (greater than 2000%) and the rest during one week of storage at 12 ° C under little agitation. After three weeks of storage under these conditions, the dilution It is 1000%.

This resin is used to formulate four gluing compositions, of which three based on one premix of resol and urea, where the formulas are presented in the table 1 below.

These sizing are used in a line of manufacture of glass wool based insulation products: gluing is diluted so that it is sprayed on the filaments of glass wool before reception on a band conveyor contained in a reception chamber provided with suction means to force the glass wool on the band. The conveyor belt passes into a fit zone where the glass wool can be compressed vertically and eventually longitudinally, then transports the shaped mass to a binder crosslinking stove where a reign reigns temperature of 280ºC approximately.

The binder agent content of the product it is measured by the loss to fire of the latter, which is here of 4.5% of the total product weight.

Samples of gaseous emissions are taken in all points of the manufacturing line, in particular, in the training area, at the entrance and exit of the stove, and assess the phenol, formalin and ammonia contained in these samples. Cumulative emissions throughout the line are listed in the table 1 below.

Trial 1 shows that by adding ammonium sulphite, certainly the level of ammonia emissions is elevates a bit as a result of the presence of ammonium ions, but the level of free formaldehyde is extraordinarily low.

An advantageous variant is to suppress the ammonia preserving ammonium sulphite, in quantity eventually reduced

Test 2, which uses a resin premix + urea and does not resort to ammonia, gives very good emission results both in regard to formalin and ammonia.

The addition of ammonia in the premix of test 3 allows reducing the level of formaldehyde emitted, with a Ammonia emitted content that remains tolerable.

Finally, the addition of ammonium sulphite in test 4 allows to reduce the level of formalin on the other hand emitted, with an emitted ammonia content that remains the same of tolerable.

TABLE 1

one

Example 2

A resin is prepared form-phenolic introducing into a low reactor agitation to be maintained throughout the manufacturing cycle, 100 kg of phenol and 276 kg of formaldehyde in 37% aqueous solution, and bring the temperature in the reactor to 45 ° C. Molar relationship formaldehyde / phenol is 3.2.

While maintaining the temperature at 45 ° C, are introduced regularly in a time of 30 minutes 12.7 kg of sodium hydroxide in 47% aqueous solution, either with a 6% soda / phenol weight ratio, or with a ratio 14.1% molar.

Immediately after the end of this addition, the temperature is increased to 70 ° C in 30 minutes, and maintains this temperature for a time of approximately 130 minutes At the end of this time, the resolvability of the resol neutralized by sulfuric acid is 1200%.

The reactor and the mixture are then cooled of the reaction from 70 ° C to 35 ° C in 35 minutes.

The pH of the medium of the reaction at 7.3 with sulfamic acid in 15% aqueous solution (approximately 88 kg). The operation takes 90 minutes approximately, while cooling the reaction mixture at 20 ° C.

The neutralized resol has a rate of 2.5% free formalin, and a free phenol rate of 0.5% by weight of resol, for a dry extract of 36%.

The solubility of the resol neutralized by the sulfamic acid is 1800% and passes to 1300% after three weeks storage at 12 ° C under little agitation.

This resin is used to formulate two gluing compositions based on a premix of resol and urea, whose formulas are presented in table 1.

These sizing are used as in example 1 for the manufacture of insulating product based on glass wool, and the results of gaseous emission measures are included in the Table 1.

Trial 1 shows that despite the presence of ammonia in the glue, the level of ammonia emitted it is still tolerable, and can very simply be reduced if suppresses ammonia as shown by partial suppression of ammonia in trial 2.

The level of formalin and phenol emissions in These two trials are on the other hand very satisfactory.

Claims (13)

1. Insulating product based on mineral wool glued with a binder based on a form-phenolic resin, characterized in that the binder comprises in mixture:

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 60 to 90 parts by weight of a phenol-formaldehyde resol that has a free formaldehyde rate of 25% or less in weight with respect to the dry weight of resin and a free phenol rate less than or equal to 2.5% by weight with respect to the dry resin weight obtained by condensation in basic medium of phenol (P) and of formaldehyde (F) in a F / P molar ratio of the order of 2.5 to 4 until the condensation product neutralized by acid sulfuric acid has a dilution with water greater than 500% and less or equal to 1500%;

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10 a 40 parts by weight of urea.

2. Insulating product according to claim 1, characterized in that the free phenol rate of the resol before the urea addition is less than or equal to 2% with respect to the dry weight of resin, in particular of the order of 0.5 to 1.7% with respect to the dry weight of resin. 3. Insulating product according to claim 1 or 2, characterized in that the rate of free formaldehyde before the addition of urea is less than or equal to 20% with respect to the dry resin weight. 4. Insulating product according to any one of the preceding claims, characterized in that the F / P ratio is of the order of 2.5 to 3.2. 5. Insulating product according to any one of the preceding claims, characterized in that the resol is obtained by reacting the phenol and formaldehyde, in the presence of a basic catalyst such as soda, at a temperature of the order of 50 to 80 ° C, in particular, from 60 to 75 ° C, in particular approximately 70 ° C, for a time of the order of 80 to 200 minutes, in particular, from 90 to 150 minutes. 6. Insulating product according to any one of the preceding claims, characterized in that the resol is neutralized by at least one acid chosen from boric acid or an equivalent borate, sulfamic acid or an equivalent sulfamate, an amino acid. 7. Insulating product according to any one of the preceding claims, characterized in that the mixture comprises 60 to 90 parts by dry weight of resol for 40 to 10 parts by weight of urea, preferably at least 65 parts, in particular 70 to 85 parts in dry weight of resol for at most 35 parts, in particular 15 to 30 parts by weight of urea. 8. Insulating product according to any one of the preceding claims, characterized in that the binding agent further comprises 1 to 10 parts by weight of ammonium sulphite for 100 parts by dry weight of resol and urea. 9. Gluing composition for insulating product, characterized in that it comprises in mixture:

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 60 to 90 parts by weight of a phenol-formaldehyde resol that has a free formaldehyde rate of 25% or less in weight with respect to the dry weight of resin and a free phenol rate less than or equal to 2.5% by weight with respect to the dry resin weight obtained by condensation in basic medium of phenol (P) and of formaldehyde (F) in a F / P molar ratio of the order of 2.5 to 4 until the acid neutralized condensation product sulfuric acid has a dilution with water greater than 500% and less or equal to 1500%;

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 10 a 40 parts by weight of urea.

10. The sizing composition according to claim 9, characterized in that the mixture comprises 60 to 90 parts by dry weight of resol for 40 to 10 parts by weight of urea, preferably 70 to 85 parts by dry weight of resol for 15 to 30 parts by weight of urea. 11. The sizing composition according to claim 9 or 10, characterized in that it further comprises 1 to 20 parts by weight of ammonium sulphite for 100 parts by dry weight of resol and urea. 12. Use of a sizing composition according to any one of claims 9 to 11 to reduce the Ammonia emissions during the manufacture of a product insulating. 13. Method of manufacturing an insulating product based on mineral wool glued with a formho-phenolic binder, characterized in that a sizing composition according to any one of claims 9 to 11 is sprayed on the mineral wool and because the ammonia emissions accumulated in all stages of manufacture are less than 10 grams of ammonia per kilogram of mineral wool.